Great video... I see the fan is not turning... Did you disconnect the water pump by taking the belt off?
The WP belts were shot so it was shut off at the end of the video to keep it from getting too hot. The old Mack gas pedal was stuck at the hinge point from sitting so I just idled it up to check the driveline and the brakes. The old gal ran pretty good after blowing the cobwebs out.
Nice find. Tough trucks too! Mack had a big name in both on and off road work. We had many with the gas Thermodyne's as power. Dependable and well built. Good luck with this. If you need a parts source send me a P/M and I'll give you some long winded addresses. These are popular in South America still. Normbc9
Now I know what cab and grille I have. I picked one up out of a salvage yard fairly complete,tach speeddo, everything even the air operated wipers. Moved to inside the shop. Stamp in cab has date of Feb. 1951. If I recall the front fenders are still at the yard along with the rest of the truck.
Old bullets; darned if I haven't learned something else new today! I also save the cardboard that new head gaskets come in wrapped in plastic. Victor and McCord packaging has made hundreds of gaskets! Tom S. in Tn.